#pragma once

/*

//计算代码段运行时间的类

//

*/

#include <iostream>

#ifndef ComputeTime_h

#define ComputeTime_h

class   ComputeTime

{

private:

	int Initialized;

	__int64 Frequency;

	__int64 BeginTime;  

public:  

	bool Avaliable();

	double End();

	bool Begin();

	ComputeTime();

	virtual   ~ComputeTime();    

};  

#endif

#include "stdafx.h"

#include "ComputeTime.h"

#include <iostream>

#include <Windows.h>

ComputeTime::ComputeTime()

{

	Initialized=QueryPerformanceFrequency((LARGE_INTEGER   *)&Frequency);

}  

 ComputeTime::~ComputeTime()

{  

}  

 bool   ComputeTime::Begin()

{

	if(!Initialized)

		return 0;

	 return   QueryPerformanceCounter((LARGE_INTEGER   *)&BeginTime);

 }

 double   ComputeTime::End()

{

	 if(!Initialized)

		return 0;

	 __int64   endtime;  

	 QueryPerformanceCounter((LARGE_INTEGER   *)&endtime);  

	 __int64   elapsed = endtime-BeginTime;  

	 return   ((double)elapsed/(double)Frequency)*1000.0;  //单位毫秒

 }  

 bool   ComputeTime::Avaliable()

{

	 return Initialized;

}